Transfer recording method using reactive sublimable dyes

ABSTRACT

The transfer recording method which comprises heating a transfer sheet having a color material layer containing a sublimable dye on a base according to the image information received, thereby subliming said sublimable dye and transfer recording it on an image receiving layer of a recording sheet, a transfer recording method which is characterized by that the image receiving layer of the recording sheet contains a compound capable of reacting with the sublimable dye contained in the color material layer of the transfer sheet.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a transfer recording method.

2. Description of the Prior Art

In office automation terminal such as facsimiles, printers, copyingmachines etc. which have lately been rapidly spread, there has been anincreasing demand for color recording having a capacity for a greatamount of information and also being visually preferable. On the otherhand, the development of techniques of color recording of televisionimages has been sought.

Currently, for these purposes, color recording techniques by electronphotography, an ink-jet process, a heat-sensitive transfer process etc.are being under study.

Of those, the heat-sensitive transfer process is more advantageous ascompared with the other processes since the maintenance and operation ofthe device are easier and the device and expendable supplies are lessexpensive.

The heat-sensitive transfer process may be classified into two, namely,a molten transfer process which comprises heat melting a dye layerformed on a base using a heat-sensitive head, thereby transfer recordingon a recording sheet, and a sublimation transfer process which comprisesforming a dye layer containing a sublimable dye on a base and heating itby a heat-sensitive head, thereby subliming the dye and transferrecording on a recording sheet, and the latter is believed particularlyadvantageous for full color recording, because gradation recording iseasy since it is possible to control the amount of the dye to besublimed and transferred by controlling the energy applied to theheat-sensitive head.

The dye for use in the above-described sublimation transfer process isdesirably a dye as much sublimable as possible in order to reduce theburden on the heat-sensitive head or to increase the recording speed,but such an easily sublimable dye, during a long-term storage period orunder high-temperature, high-moisture environment, had a problem withthe recording stability, because the dye re-sublimed from the recordingsheet and hence deteriorated the recording and migrated to contractedobjects thus staining them.

As a method for solving such a problem, it is contemplated to preventthe re-sublimation by laminating the surface of the recording sheet witha resin film after transfer recording.

However, in such a method, since it is necessary to use a material and adevice for laminating and also the device assembly itself becomes largerand more complicated, further improvement is being desired.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a method forobtaining a transfer recording having excellent storage stability.

In other words, this invention resides in a transfer recording methodwhich comprises heating a transfer sheet having a color material layercontaining a sublimable dye on a base according to the image informationreceived, thereby subliming said sublimable dye and transfer recordingit on an image receiving layer of a recording sheet, which transferrecording method is characterized by that the image receiving layer ofthe recording sheet contains a compound capable of reacting with thesublimable dye contained in the color material layer of the transfersheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The transfer sheet used in the transfer recording method of thisinvention may be obtained by mixing a sublimable dye with an appropriateresin and solvent, water etc. to prepare an ink, coating said ink on anappropriate base and then drying thereby forming a color material layer.

The sublimable dye used in this invention may be selected from a widevariety of sublimable dyes usually used for sublimation typeheat-sensitive transfer recording, and examples thereof are described indetail:

[A] Sublimable Dyes Capable of Reacting with an Epoxy Group or anIsocyanate Group:

The following dyes fall in this category: styrylic, indoaniline type,naphthoquinone type, azo type, anthraquinone type, nitro type,quinophthalone type, methine type and the like sublimable dyes havingsuch groups as amino group, alkylamino group, hydroxyl group, carboxylgroup, amido group, mercapto group etc. That is:

(i) The aforesaid styrylic dyes include styrylic dyes of the generalformula [I]: ##STR1## wherein X is hydrogen or methyl, R¹ ishydroxyalkyl, dialkylaminoalkyl, hydroxycarbonylalkyl, acylaminoalkyl ormercaptoalkyl, and R² is alkyl or hydroxyalkyl, and styrylic dyes of thegeneral formula [II]: ##STR2## wherein R³ is hydrogen, hydroxyalkyl ordialkylaminoalkyl, and R² is as defined above.

Examples of preferred styrylic dyes are those of the followingstructural formulae: ##STR3## (ii) The aforesaid indoaniline type dyesinclude indoaniline type dyes of the general formula [III]: ##STR4##wherein n is 0 or 1, R⁴ is alkyl or alkoxyalkyl, Y¹, Y² and X¹ are eachhydrogen, methyl, methoxy, halogen, acylamino or alkoxycarbonylamino,and R² and R³ are as defined above.

Examples of preferred indoaniline type dyes are those of the followingstructural formulae: ##STR5## (iii) The aforesaid naphthoquinone typedyes include naphthoquinone type dyes of the general formula [IV]:##STR6## wherein R⁵ is hydrogen, hydroxyalkyl or dialkylaminoalkyl, andR⁶ is hydrogen, alkyl, hydroxyalkyl or dialkylaminoalkyl, and anaphthoquinone type dye of the structural formula: ##STR7## Examples ofpreferred naphthoquinone dyes are those of the following structuralformulae: ##STR8## (iv) The aforesaid azo type dyes include azo typedyes of the general formula [XXXI]: ##STR9## wherein A⁴ is optionallysubstituted phenyl, and R¹ is as defined above, and azo type dyes of thefollowing structural formulae: ##STR10## (v) The aforesaid anthraquinonetype dyes include anthraquinone type dyes of the general formula[XXXII]: ##STR11## wherein X⁴ is --O-- or --S--, and R¹ is as definedabove, and anthraquinone type dyes of the following structural formulae:##STR12## (vi) The aforesaid nitro type dyes include a nitro type dye ofthe following structural formula: ##STR13## (vii) The aforesaidquinophthalone type dyes include a quinophthalone type dye of thefollowing structural formula: ##STR14## [B] Sublimable Dyes Having aVinylsulfone Group:

The following dyes fall in this category: azo type, anthraquinone type,nitro type, naphthoquinone type, quinophthalone type and the likesublimable dyes having a vinylsulfone group. That is:

(i) The aforesaid azo type dyes include azo type dyes of the generalformula [V]: ##STR15## wherein A¹ is optionally substituted aminophenyl,pyrazolone, pyridone or pyridinyl, and R⁷ and R⁸ are each hydrogen,alkyl or alkoxy.

Examples of preferred azo type dyes are those of the followingstructural formulae: ##STR16## (ii) The aforesaid anthraquinone typedyes include anthraquinone type dyes of the general formula [VI]:##STR17## wherein R⁹ is hydrogen or alkyl, R¹⁰ is hydrogen or cyano, andR⁷ and R⁸ are as defined above.

Examples of preferred anthraquinone type dyes are those of the followingstructural formulae: ##STR18## (iii) The aforesaid nitro type dyesinclude nitro type dyes of the general formula [VII]: ##STR19## whereinR⁷ and R⁸ are as defined above. Examples of preferred nitro type dyesare those of the following structural formulae: ##STR20## (iv) Theaforesaid naphthoquinone type dyes include naphthoquinone type dyes ofthe general formula [XVIII] or [XIX]: ##STR21## wherein R⁷, R⁸ and R⁹are as defined above. Examples of preferred naphthoquinone type dyes arethose of the following structural formulaes: ##STR22## (v) The aforesaidquinophthalone type dyes include quinophthalone type dyes of the generalformula [XX]: ##STR23## wherein X³ is hydrogen or halogen. Examples ofpreferred quinophthalone type dyes are those of the following structuralformulae: ##STR24## [C] Sublimable Dyes having an Epoxy Group:

The following dyes fall in this category: azo type, anthraquinone type,naphthoquinone type, styrylic, indoaniline type, quinophthalone type,azomethine type and the like sublimable dyes having an epoxy group. Thatis:

(i) The aforesaid azo type dyes include azo type dyes of the generalformula [VIII]: ##STR25## wherein A² is optionally substituted phenyl,benzothiazolyl, imidazolyl or thienyl, R¹¹ is hydrogen, alkyl oralkylcarbonylamino, and R¹² is alkyl.

Examples of preferred azo type dyes are those of the followingstructural formulae: ##STR26## (ii) The aforesaid anthraquinone typedyes include anthraquinone type dyes of the general formula [IX] or [X]:##STR27## wherein R¹³ and R¹⁴ are each hydrogen, alkyl or ##STR28## R¹⁵is hydrogen or ##STR29## and R¹⁶ and R¹⁷ are each hydrogen or alkyl,with the proviso that when R¹³ and R¹⁴ are both hydrogen or alkyl, theR¹⁵ is ##STR30## Examples of preferred anthraquinone type dyes are thoseof the following structural formulae: ##STR31## (iii) The aforesaidnaphthoquinone type dyes include naphthoquinone type dyes of the generalformula [XI] or [XXI]: ##STR32## wherein R¹³ is as defined above.Examples of preferred naphthoquinone type dyes are those of thefollowing structural formulae: ##STR33## (iv) The aforesaid styrylicdyes include styrylic dyes of the general formula [XII]: ##STR34##wherein R¹⁰, R¹¹ and R¹² are as defined above. Examples of preferredstyrylic dyes are those of the following structural formulae: ##STR35##(v) The aforesaid indoaniline type dyes include indoaniline type dyes ofthe general formula [XIII]: ##STR36## wherein n, R⁴, R¹², Y¹, Y² and X¹are as defined above, and indoaniline type dyes of the general formula[XXII]: ##STR37## wherein R²⁰ is hydrogen or alkylaminocarbonyl,##STR38## and R¹¹ and R¹² are as defined above. Examples of preferredindoaniline type dyes are those of the following structural formulae:##STR39## (vi) The aforesaid quinophthalone type dyes includequinophthalone type dyes of the general formula [XXIII]: ##STR40##wherein --X² -- is --O-- or --NH--. Examples of preferred quinophthalonetype dyes are those of the following structural formulae: ##STR41##(vii) The aforesaid azomethine type dyes include azomethine type dyes ofthe general formula [XXIV]: ##STR42## wherein A is ##STR43## R²¹ and R²²are each alkyl, and R¹¹ and R¹² are as defined above.

Examples of preferred azomethine type dyes are those of the followingstructural formulae: ##STR44## [D] Sublimable Dyes Having an AcryloylGroup or a Methacryloyl Group

The following dyes fall in this category: styrylic, indoaniline type,azo type, anthraquinone type, naphthoquinone type, azomethine type andthe like sublimable dyes having an acryloyl group or a methacryloylgroup. That is:

(i) The aforesaid styrylic dyes include styrylic dyes of the generalformula [XIV]: ##STR45## wherein R¹⁸ is alkyl, R¹⁹ is acryloyl ormethacryloyl, and R¹⁰, R¹¹ and R¹⁹ are as defined above.

Examples of preferred styrylic dyes are those of the followingstructural formulae: ##STR46## (ii) The aforesaid indoaniline type dyesinclude indoaniline type dyes of the general formula [XV]: ##STR47##wherein n, R⁴, R¹⁸, R¹⁹, Y¹, Y², X¹ and X² are as defined above, andindoaniline type dyes of the general formula [XXV]: ##STR48## wherein##STR49## and R¹¹, R¹⁸, R¹⁹, R²⁰ and X² are as defined above.

Examples of preferred indoaniline type dyes are those of the followingstructural formulae: ##STR50## (iii) The aforesaid azo type dyes includeazo type dyes of the general formula [XVI]: ##STR51## wherein A³ isoptionally substituted phenyl, thienyl or thiadiazolyl, and R¹¹, R¹⁸,R¹⁹ and X² are as defined above, and azo type dyes of the generalformula [XVII]: ##STR52## wherein A⁴ is optionally substituted phenyl,and R¹⁹ and X² are as defined above.

Examples of preferred azo type dyes are those of the followingstructural formulae: ##STR53## (iv) The aforesaid anthraquinone typedyes include anthraquinone type dyes of the general formula [XXXIII]:##STR54## wherein X⁵ is alkylene, and X², X⁴ and R¹⁹ are as definedabove, and anthraquinone dyes of the general formula [XXVI]: ##STR55##wherein R²³ is hydrogen or --COO--C₂ H₄ --X² --R¹⁹, and R⁹, R¹⁸ and X²are as defined above, with the proviso that when R¹⁸ is alkyl, then R²³is --COO--C₂ H₄ --X² --R¹⁹.

Examples of preferred anthraquinone type dyes are those of the followingstructural formulae: ##STR56## (v) The aforesaid naphthoquinone typedyes include naphthoquinone type dyes of the general formula [XXVIII] or[XXIX]: ##STR57## wherein R¹⁸, R¹⁹ and X² are as defined above. Examplesof preferred naphthoquinone type dyes are those of the followingstructural formulae: ##STR58## (vi) The aforesaid azomethine type dyesinclude azomethine type dyes of the general formula [XXX]: ##STR59##wherein A⁵, R¹¹, R¹⁸, R¹⁹ and X² are as defined above.

Examples of preferred azomethine type dyes are those of the followingstructural formulae: ##STR60##

As the resin for preparing the above-described ink, that having a highmelting point or softening point is suitable, and specific examples ofsuitable resins include phenolic resins, melamine resins, urethaneresins, epoxy resins, silicone resins, urea resins, diallyl phthalateresins, alkyd resins, acetal resins, acrylic resins, methacrylic resins,polyester resins, starch and derivatives thereof, cellulosic resins,polyvinyl chloride, polyvinylidene chloride, fluorine resins,chlorinated polyethylene, polyethylene, polypropylene, polystyrene,polyvinyl acetal, polyvinyl alcohol, polycarbonates, polysulfones,polyether sulfones, polyethylene terephthalate, polybutyleneterephthalate, polyphenylene oxide, polyphenylenesulfinde, polyethylenenaphthalate, polyacrylonitrile, polyimides, polyamides, AS resins, ABSresins etc.

Particularly preferred resins are such inert resins as methyl cellulose,polyvinyl alcohol, hydroxypropylmethyl cellulose, hydroxyethylcellulose, polysulfones, polyether sulfones, polyethylene terephthalate,polycarbonates, ethyl cellulose, cellulose acetate, acrylic resins etc.

Examples of the solvent used for preparing the ink include alcohols suchas methanol, ethanol, propanol, butanol etc., cellosolves such as methylcellosolve, ethyl cellosolve etc., aromatics such as benzene, toluene,xylene, chlorobenzene etc., esters such as ethyl acetate, butyl acetateetc., ketones such as acetone, methyl ethyl ketone, methyl isobutylketone, cyclohexanone etc., hydrocarbons such as ligroine, cyclohexane,kerosene etc., chlorine type solvents such as chloroform, methylenechloride, trichloroethylene etc., dimethylformamide etc., and where awater-based resin is used, it is also possible to use water or water inmixture with the above-described solvents.

Particularly preferred solvents are such inert solvents as benzene,toluene, xylene, chlorobenzene, acetone, methyl ethyl ketone,chloroform, methylene chloride etc.

The base for the transfer sheet is suitably tissue paper such ascondenser paper, glassin paper etc. or a film of a plastic having goodheat resistance, such as polyesters, polyamides and polyimides. Such abase had to be thin in order to increase the heat transfer coefficiencyfrom the heat-sensitive head to the dye etc., and thus a thickness ofnot greater than 50 μm is suitable, preferably not greater than 20 μm.

The recording sheet used in the transfer recording method of thisinvention may be obtained by coating an appropriate base, for example,paper, a resin film etc. with a coating solution containing a compoundcapable of reacting with the sublimable dye contained in the colormaterial layer of the transfer sheet, and then drying to form an imagereceiving layer.

On that occasion, the coating solution may also contain a resin such aspolyesters, polyamides, polyacrylates etc., inorganic fine particlessuch as silica, alumina, calcium carbonates etc., and the like.

Examples of the compound capable of reacting with the sublimable dyecontained in the color material layer of the transfer sheet include thefollowing:

[a] In the Case where the Sublimable Dye Contained in the Color MaterialLayer of the Transfer Sheet is a Sublimable Dye Capable of Reacting withan Epoxy Group or an Isocyanate Group Described in the Aforesaid [A]:

Compounds having an epoxy group, an isocyanate group or a blockedisocyanate group fall in this category.

(i) The compounds having an epoxy group include various known polymersand monomers containing one or more epoxy groups, and specific examplesthereof are those having the following structural formulae: ##STR61##(ii) The compounds having an isocyanate group include various knownisocyanate compounds, and specific examples thereof are those having thefollowing structural formulae: ##STR62## (iii) The compounds having ablocked isocyanate group include those which will produce an isocyanategroup upon heating on heat transfer, and specific examples thereofinclude compounds obtained by inactivating (masking) the above-describedisocyanate compounds with ethanol, phenol, cresol, diethyl maleate,ethyl acetoacetate, acetylacetone etc.

[b] In the Case where the Sublimable Dye Contained in the Color MaterialLayer of the Transfer Sheet is the Sublimable Dye Having a VinylsulfonylGroup Described in the Aforesaid [B] or the Sublimable Dye Having anAcryloyl Group or a Methacryloyl Group Described in the Aforesaid [D]:

Active hydrogen compounds fall in this category, and include variousknown polymers and low molecular weight compounds containing e.g. ahydroxyl group, a mercapto group, a carboxyl group, an amino group, amonoalkylamino group, or an amido group, preferably, a hydroxyl group, acarboxyl group or an amino group. Specific examples thereof are thefollowing:

(i) Compounds having an OH group: ##STR63## (ii) Compounds having amercapto group: ##STR64## (iii) Compounds having a carboxyl group:##STR65## (iv) Compounds having an amino group, a monoalkyl group or anamido group: ##STR66## (v) Compounds having various groups: ##STR67##[c] In the Case where the Sublimable Dye Contained in the Color MaterialLayer of the Transfer Sheet is the Sublimable Dye Having a Epoxy GroupDescribed in the Aforesaid [C]:

The active hydrogen compounds described in the aforesaid [b] or organicacid anhydride fall in this category.

Specific examples of organic acid anhydride include the following:##STR68##

Heat-sensitive transfer recording using the transfer sheet and recordingsheet obtained above may be effected by overlapping both in such waythat the color material of the transfer sheet and the image receivinglayer of the recording sheet be inside, and heating and pressing theassembly from the back side of the transfer sheet using a heat-sensitiverecording head.

Where transfer recording is conducted by the above-described method,since the dye in the transfer sheet is not only sublimed and transferredto the recording sheet but also reacts with the compound capable ofreacting therewith in the recording sheet, the fixation of the dye isensured, thereby giving recording having excellent storage stability.

As evident from the preceding description and the examples describedhereinbelow, recording having excellent storage stability may be readilyand simply obtained by this invention.

This invention is more particularly described by the following examplesand preparation examples, but it will be noted that these examples aremerely illustrative and do not restrict this invention.

EXAMPLE 1

(1) Process for the Preparation of a Transfer Sheet

    ______________________________________                                         ##STR69##                                                                

    ______________________________________                                        Sublimable dye having the above                                                                        2      g                                             structural formula                                                            Ethyl cellulose          8      g                                             Isopropanol              90     g                                             Total                    100    g                                             ______________________________________                                    

A mixture having the above composition was mixed and conditioned withglass beads using a paint conditioner for about 30 minutes to prepare anink.

The above ink was coated on a condenser paper sheet (10 μm in thickness)using a gravure printer (30 μm in block depth) and thereafter dried inair to prepare a transfer sheet.

(2) Process for the Preparation of a Recording Sheet

    ______________________________________                                         ##STR70##                                                                

    ______________________________________                                        Isocyanate compound having the above                                                                    5      g                                            structural formula                                                            Polyester resin*          15     g                                            Methyl ethyl ketone       80     g                                            Total                     100    g                                            ______________________________________                                         *"VYLON 200" (tradename) produced by Toyo Spinning Co., Ltd.             

The above composition was mixed to prepare a coating solution.

The above obtained coating solution was coated on a wood free papersheet using a gravure printer (30 μm in block depth) and dried in air toprepare a recording sheet.

(3) Method of Transfer Recording The aforesaid transfer sheet wasoverlapped with the recording sheet with the ink coated surface of theformer and the coating solution coated surface of the latter inside, andheated from the back surface of the transfer sheet using aheat-sensitive head, thereby recording in a brilliant deep yellow colorwas successfully obtained on the recording sheet.

In order to test the stability of the recording thus obtained, therecorded surface was overlapped with a wood free paper sheet andmaintained under pressure of 200 g/cm² at 80° C. for 24 hours, and as aresult, there was hardly observed any change in the color of the recordor any staining on the wood free paper sheet due to the dye.

REFERENCE EXAMPLE 1 (Synthesis of the Dye of Example 1)

62.1 g of a compound of the following structural formula: ##STR71## wasdissolved in 420 ml of IPA (isopropyl alcohol), 19.8 g of malonitrileand 1.5 ml of piperidine were added thereto, then the mixture was heatedto 80° C. and reacted at 80° C. for 2 hours. After cooling, methanol wasadded, the precipitated crystals were filtered, washed with water anddried to obtain 62 g of yellow crystals.

The obtained dye had a maximum absorption wavelength (λmax: chloroform)of 448 nm.

COMPARATIVE EXAMPLE 1

(1) Process for the Preparation of a Transfer Sheet

A transfer sheet was prepared in a manner similar to that in Example 1.

(2) Process for the Preparation of a Recording Sheet

A coating solution was prepared by dissolving 15 g of a polyester resin(VYLON 200) in 85 g of methyl ethyl ketone, and coated on a wood freepaper sheet in a manner similar to that in Example 1 to prepare arecording sheet.

(3) Method of Transfer Recording

The aforesaid transfer sheet and recording sheet were overlapped andtransfer recording was conducted in a manner similar to that in Example1 to obtain a record in a deep yellow color.

The thus obtained recording was tested for stability in a manner similarto that in Example 1, and, as a result, it was observed that theoverlapped wood free paper sheet had been remarkably stained due to themigration of the dye from the recording sheet. Further, the colordensity of the recording sheet was remarkably reduced due to themigration of the dye.

EXAMPLE 2

A transfer sheet was prepared by using a sublimable dye of thestructural formula: ##STR72## instead of the sublimable dye used inExample 1, and a recording sheet was prepared by using an epoxy compoundof the structural formula: ##STR73## instead of the isocyanate compoundused in Example 1, and thereafter transfer recording was conducted in amanner similar to that in Example 1 to obtain a record in a brilliantdeep red color. This record was tested for stability in a manner similarto that in Example 1, and as a result, there was hardly observed anychange in the color of the record or any staining of the wood free paperdue to the dye.

REFERENCE EXAMPLE 2 (Synthesis of the Dye of Example 2)

6.1 g of a compound of the structural formula: ##STR74## was dissolvedin 15 ml of N,N-dimethylformamide, then 3.8 g of tetracyanoethylene wasgradually added thereto, and stirred at 40°-50° C. for 2 hours. Aftercooling, 100 ml of a 90% methanolic aqueous solution was added, and theprecipitates were filtered off. They were washed with methanol and thenwith water, and dried to obtain 5.2 g of dark red crystals.

The obtained dye had a melting point of 162°-168° C. and a maximumabsorption wavelength (λmax: chloroform) of 521 nm.

COMPARATIVE EXAMPLE 2

Using the transfer sheet prepared in Example 2 and a recording sheetprepared in a manner similar to that in Example 2 except that the epoxycompound used in Example 2 was not used, transfer recording and a teston the recording stability were conducted similarly, and as a result,there were observed a remarkable reduction in the color density andremarkable staining of the overlapped paper due to the dye.

EXAMPLE 3

A transfer sheet was prepared by using a sublimable dye of thestructural formula: ##STR75## instead of the sublimable dye used inExample 1, and a recording sheet was prepared by using a blockedisocyanate compound of the structural formula: ##STR76## instead of theisocyanate compound used in Example 1, and thereafter transfer recordingwas conducted in a manner similar to that in Example 1 to obtain arecord in a brilliant deep blue color. This record was tested forstability in a manner similar to that in Example 1, and as a result,there were hardly observed any change in the color of the record or anystaining of the overlapped wood free paper sheet due to the dye.

REFERENCE EXAMPLE 3 (Synthesis of the Dye of Example 3)

Nitrogen gas was adequately blown into 90 ml of methanol, 30 g of acompound of the structural formula: ##STR77## was added thereto, themixture was cooled to 30° C. or below, 2.10 g of hydroxyethylamine wasadded thereto and reacted at 40° C. for 2 hours and then at 60° C. foran hour, after which 90 ml of NMP (N-methylpyrrolidone) was added, themixture was cooled to room temperature, and stirred at room temperaturewhile slowly passing air for 5 hours thereby effecting oxidation. Theprecipitated crystals were filtered off to obtain 23.0 g of dark bluecrystals.

The obtained dye had a maximum absorption wavelength (λmax: chloroform)of 650 nm.

COMPARATIVE EXAMPLE 3

Using the transfer sheet prepared in Example 3 and a recording sheetprepared in a manner similar to that in Example 3 except that theblocked isocyanate compound was not used, transfer recording and a teston the recording stability were conducted, and as a result, there wereobserved a remarkable reduction in the color density and remarkablestaining of the overlapped wood free paper sheet due to the dye.

EXAMPLE 4

Using various sublimable dyes of the structural formulae set forth inTable 1 synthesized according to Reference Examples 1-3 instead of thesublimable dye used in Example 1, transfer sheets were prepared, andtransfer recording was conducted in a manner similar to that in Example1, thereby it was possible to obtain records having good stability,respectively.

                                      TABLE 1                                     __________________________________________________________________________                                          Max. Absorption                                                         Color of                                                                            Wavelength λmax                  No.                                                                              Dye                          the Record                                                                          (chloroform) (nm)                       __________________________________________________________________________        ##STR78##                   Yellow                                                                              444                                     2                                                                                 ##STR79##                   Yellow                                                                              446                                     3                                                                                 ##STR80##                   Yellow                                                                              448                                     4                                                                                 ##STR81##                   Yellow                                                                              448                                     5                                                                                 ##STR82##                   Yellow                                                                              412                                     6                                                                                 ##STR83##                   Blue  650                                     7                                                                                 ##STR84##                   Yellow                                                                              505                                     8                                                                                 ##STR85##                   Red   520                                     9                                                                                 ##STR86##                   Blue  595                                     10                                                                                ##STR87##                   Red   540                                     11                                                                                ##STR88##                   Blue  671                                     12                                                                                ##STR89##                   Blue  625                                     13                                                                                ##STR90##                   Yellow                                                                              438                                     14                                                                                ##STR91##                   Red   496                                     15                                                                                ##STR92##                   Red   530                                     16                                                                                ##STR93##                   Red   515                                     17                                                                                ##STR94##                   Red   493                                     18                                                                                ##STR95##                   Red   521                                     19                                                                                ##STR96##                   Blue  643                                     20                                                                                ##STR97##                   Yellow                                                                              430                                     21                                                                                ##STR98##                   Blue  633                                     22                                                                                ##STR99##                   Blue  633                                     23                                                                                ##STR100##                  Blue  626                                     24                                                                                ##STR101##                  Blue  627                                     25                                                                                ##STR102##                  Blue  652                                     26                                                                                ##STR103##                  Blue  646                                     27                                                                                ##STR104##                  Blue  635                                     __________________________________________________________________________

EXAMPLE 5

A transfer sheet was prepared by using a sublimable dye of thestructural formula: ##STR105## instead of the sublimable dye used inExample 1, and a recording sheet was prepared by using an activehydrogen compound of the structural formula: ##STR106## instead of theisocyanate compound used in Example 1, and thereafter transfer recordingwas conducted in a manner similar to that in Example 1 to obtain arecord in a brilliant deep yellow color. This record was tested forstability in a manner similar to that in Example 1, and as a result,there were hardly any change in the color of the record or any stainingof the wood free paper sheet due to the dye.

REFERENCE EXAMPLE 4 (Synthesis of the Dye of Example 5)

1.83 g of the compound of the structural formula: ##STR107## wassuspended in 50 ml of water, dissolved therein by adding 4 ml of conc.hydrochloric acid and cooled, after which 0.83 g of sodium nitrite wasadded thereto and stirred at 0°-5° C. for 4 hours. This diazo solutionwas poured into a mixture of 1.64 g of a compound of the structuralformula: ##STR108## 200 ml of methanol, 2 g of urea, 10 g of sodiumacetate and 80 g of ice. The mixture was stirred until reaching roomtemperature, filtered, washed with water and dried to obtain a dye ofthe structural formula: ##STR109##

COMPARATIVE EXAMPLE 4

Using the transfer sheet prepared in Example 5 and a recording sheetprepared in a manner similar to that in Example 5 except that the activehydrogen compound was not used, transfer recording and a test on therecording stability were conducted, and as a result, the overlapped woodfree paper sheet was remarkably stained in a yellow color due to themigration of the dye from the recording sheet and also the color densityof the recording sheet was remarkably reduced due to the migration ofthe dye.

EXAMPLE 6

Transfer recording was conducted in a manner similar to that in Example5 except that the dye used in Example 5 was replaced by various dyes ofthe structural formulae set forth in Table 2, thereby it was possible toobtain records having good storage stability, respectively.

                                      TABLE 2                                     __________________________________________________________________________                                               Max. Absorption                                                         Color of                                                                            Wavelength (λmax)           No.                                                                              Dye                               the Record                                                                          (chloroform)                       __________________________________________________________________________                                               (nm)                                   ##STR110##                       Yellow                                                                              460                                2                                                                                 ##STR111##                       Yellow                                                                              420                                3                                                                                 ##STR112##                       Red   510                                4                                                                                 ##STR113##                       Yellow                                                                              470                                5                                                                                 ##STR114##                       Red   519                                6                                                                                 ##STR115##                       Blue  660                                7                                                                                 ##STR116##                       Blue  662                                8                                                                                 ##STR117##                       Blue  658                                9                                                                                 ##STR118##                       Blue  650                                10                                                                                ##STR119##                       Blue  686                                11                                                                                ##STR120##                       Yellow                                                                              446                                12                                                                                ##STR121##                       Yellow                                                                              448                                13                                                                                ##STR122##                       Yellow                                                                              412                                14                                                                                ##STR123##                       Yellow                                                                              413                                15                                                                                ##STR124##                       Yellow                                                                              445                                16                                                                                ##STR125##                       Blue  710                                __________________________________________________________________________

EXAMPLE 7

Using a transfer sheet prepared by using a sublimable dye of thestructural formula: ##STR126## instead of the sublimable dye used inExample 1 and the recording sheet prepared in Example, transferrecording was conducted in a manner similar to that in Example 1 toobtain a record in a brilliant deep orange color. This record was testedfor stability in a manner similar to that in Example 1, and as a result,there were hardly observed any change in the color of the record or anystaining of the overlapped wood free paper sheet due to the dye.

REFERENCE EXAMPLE 5 (Synthesis of the Dye of Example 7)

14 g of N-ethylaniline, 14.8 g of epichlorohydrin, 10 ml of water and 15ml of ethanol were added, and reacted with stirring on a water bath for3 hours. After cooling, the mixture was separated by a separatoryfunnel, and dried with sodium sulfate.

21 g of the obtained N-ethyl-N-(2-oxy-3-chloropropyl)aniline was cooledwith ice during which 8 ml of a 50% sodium hydroxide aqueous solutionwas gradually added thereto with stirring. Thereafter, stirring wascontinued for 4 hours, the formed sodium chloride was filtered out, theorganic layer was washed with water, and dehydrated with sodium sulfate.

The obtained N-ethyl-N-glycidylaniline and the diazo solution ofp-nitroaniline were coupled to obtain a dye of the structural formula:##STR127##

m.p. 159°-162° C.

Mass spectrum M+ 326.

λmax (chloroform) 474 nm.

COMPARATIVE EXAMPLE 5

Using the transfer sheet prepared in Example 7 and a recording sheetprepared in a manner similar to that in Example 5 except that the activehydrogen compound was not used, transfer recording and a test on therecording stability were conducted, and as a result, the overlapped woodfree paper sheet was remarkably stained in an orange color due to themigration of the dye from the recording sheet and also the color densityof the recording sheet was remarkably reduced due to the migration ofthe dye.

EXAMPLE 8

Transfer recording was conducted in a manner similar to that in Example7 except that the dye used in Example 7 was replaced by various dyes ofthe structural formulae set forth in Table 3, thereby it was possible toobtain records having good storage stability, respectively.

                                      TABLE 3                                     __________________________________________________________________________                                              Max. Absorption                                                         Color of                                                                            Wavelength λmax              No.                                                                              Dye                              the Record                                                                          (chloroform) (nm)                   __________________________________________________________________________        ##STR128##                      Red   490                                 2                                                                                 ##STR129##                      Blue  620                                 3                                                                                 ##STR130##                      Blue  610                                 4                                                                                 ##STR131##                      Blue  650                                 5                                                                                 ##STR132##                      Blue  671                                 6                                                                                 ##STR133##                      Blue  650                                 7                                                                                 ##STR134##                      Blue  684                                 8                                                                                 ##STR135##                      Yellow                                                                              445                                 9                                                                                 ##STR136##                      Red   520                                 10                                                                                ##STR137##                      Red   535                                 11                                                                                ##STR138##                      Blue  670                                 12                                                                                ##STR139##                      Blue  660                                 13                                                                                ##STR140##                      Blue  650                                 14                                                                                ##STR141##                      Yellow                                                                              446                                 15                                                                                ##STR142##                      Yellow                                                                              440                                 16                                                                                ##STR143##                      Yellow                                                                              447                                 17                                                                                ##STR144##                      Blue  650                                 18                                                                                ##STR145##                      Yellow                                                                              445                                 19                                                                                ##STR146##                      Blue  690                                 20                                                                                ##STR147##                      Blue  635                                 21                                                                                ##STR148##                      Blue  635                                 22                                                                                ##STR149##                      Blue  654                                 23                                                                                ##STR150##                      Blue  629                                 24                                                                                ##STR151##                      Blue  655                                 25                                                                                ##STR152##                      Blue  626                                 26                                                                                ##STR153##                      Blue  647                                 __________________________________________________________________________

EXAMPLE 9

Using a transfer sheet prepared by using a sublimable dye of thestructural formula: ##STR154## instead of the sublimable dye used inExample 1 and the recording sheet prepared in Example 5, transferrecording was conducted in a manner similar to that in Example 1 toobtain a record in a brilliant deep yellow color. This record was testedfor stability in a manner similar to that in Example 1, and as a result,there was hardly observed any change in the color of the record or anystaining of the wood free paper sheet due to the dye.

REFERENCE EXAMPLE 6 (Synthesis of the Dye of Example 9)

2.55 g of a compound of the structural formula: ##STR155## was dissolvedin 100 ml of acetone, 1.21 g of triethylamine was added thereto andcooled with ice. Thereafter, 1.25 g of methacryloyl chloride was addeddropwise thereto at 0° C., and, after completion of the addition, themixture was stirred at the same temperature for 2 hours and then at roomtemperature for 2 hours. The reaction mixture was poured into 200 ml ofice water to precipitate crystals, which were then filtered off anddried to obtain a dye of the structural formula: ##STR156##

COMPARATIVE EXAMPLE 6

Using the transfer sheet prepared in Example 9 and a recording sheetprepared in a manner similar to that in Example 5 except that the activehydrogen compound was not used, transfer recording and a test on therecord stability were conducted, and as a result, the overlapped woodfree paper sheet was remarkably stained in a yellow color due to themigration of the dye from the recording sheet, and also the colordensity of the recording sheet was remarkably reduced due to themigration of the dye.

EXAMPLE 10

Transfer recording was conducted in a manner similar to that in Example9 except that the dye used in Example 9 was replaced by various dyeshaving the structural formulae set forth in Table 4, thereby it waspossible to obtain records having good storage stability, respectively.

                                      TABLE 4                                     __________________________________________________________________________                                              Max. Absorption                                                         Color of                                                                            Wavelength λmax              No.                                                                              Dye                              the Record                                                                          (chloroform) (nm)                   __________________________________________________________________________        ##STR157##                      Yellow                                                                              420                                 2                                                                                 ##STR158##                      Red   515                                 3                                                                                 ##STR159##                      Red   515                                 4                                                                                 ##STR160##                      Yellow                                                                              440                                 5                                                                                 ##STR161##                      Yellow                                                                              440                                 6                                                                                 ##STR162##                      Yellow                                                                              473                                 7                                                                                 ##STR163##                      Blue  671                                 8                                                                                 ##STR164##                      Blue  653                                 9                                                                                 ##STR165##                      Blue  653                                 10                                                                                ##STR166##                      Blue  654                                 11                                                                                ##STR167##                      Blue  654                                 12                                                                                ##STR168##                      Blue  685                                 13                                                                                ##STR169##                      Yellow                                                                              446                                 14                                                                                ##STR170##                      Yellow                                                                              442                                 15                                                                                ##STR171##                      Red   520                                 16                                                                                ##STR172##                      Red   520                                 17                                                                                ##STR173##                      Red   521                                 18                                                                                ##STR174##                      Yellow                                                                              444                                 19                                                                                ##STR175##                      Blue  691                                 20                                                                                ##STR176##                      Blue  630                                 21                                                                                ##STR177##                      Blue  624                                 22                                                                                ##STR178##                      Blue  650                                 23                                                                                ##STR179##                      Blue  624                                 24                                                                                ##STR180##                      Blue  650                                 25                                                                                ##STR181##                      Blue  621                                 26                                                                                ##STR182##                      Blue  642                                 __________________________________________________________________________

What is claimed is:
 1. In a transfer recording method which comprisesheating a transfer sheet having a color material layer containing asublimable dye on a base according to the image information received,thereby subliming said sublimable dye and transfer recording it on animage receiving layer of a recording sheet, a transfer recording methodwhich is characterized in that the color material layer of the transfersheet contains a sublimable dye having a vinylsulfonyl group and theimage receiving layer of the recording sheet contains an active hydrogencompound.
 2. The transfer recording method according to claim 1 whereinthe sublimable dye having a vinylsulfonyl group is an azo type dye ofthe formula: ##STR183## wherein A¹ is optionally substitutedaminophenyl, pyrazolone, pyridone or pyridinyl, and R⁷ and R⁸ are eachhydrogen, alkyl or alkoxy.
 3. The transfer recording method according toclaim 1 wherein the sublimable dye having a vinylsulfonyl group is ananthraquinone type dye of the formula: ##STR184## wherein R⁷ and R⁸ areeach hydrogen, alkyl or alkoxy, R⁹ is hydrogen or alkyl, and R¹⁰ ishydrogen or cyano.
 4. The transfer recording method according to claim 1wherein the sublimable dye having a vinylsulfonyl group is a nitro typedye of the formula: ##STR185## wherein R⁷ and R⁸ are each hydrogen,alkyl or alkoxy.
 5. In a transfer recording method which comprisesheating a transfer sheet having a color material layer containing asublimable dye on a base according to the image information received,thereby subliming said sublimable dye and transfer recording it on animage receiving layer of a recording sheet, a transfer recording methodwhich is characterized in that the color material layer of the transfersheet contains a sublimable dye having an epoxy group and the imagereceiving layer of the recording sheet contains an active hydrogencompound or an organic acid anhydride.
 6. The transfer recording methodaccording to claim 5 wherein the sublimable dye having an epoxy group isan azo type dye of the formula: ##STR186## wherein A² is optionallysubstituted phenyl, benzothiazole, imidazole or thienyl, R¹¹ ishydrogen, alkyl or alkylcarbonylamino, and R¹² is alkyl.
 7. The transferrecording method according to claim 5 wherein the sublimable dye havingan epoxy group is an anthraquinone type dye of the formula: ##STR187##wherein R¹³ and R¹⁴ are each hydrogen, alkyl or ##STR188## R¹⁵ ishydrogen or ##STR189## and R¹⁶ and R¹⁷ are each hydrogen or alkyl, withthe proviso that when R¹³ and R¹⁴ are both hydrogen or alkyl, then R¹⁵is ##STR190##
 8. The transfer recording method according to claim 5wherein the sublimable dye having an epoxy group is a naphthoquinonetype dye of the formula: ##STR191## wherein R¹³ is hydrogen, alkyl or##STR192##
 9. The transfer recording method according to claim 5 whereinthe sublimable dye having an epoxy group is a styrylic dye of theformula: ##STR193## wherein R¹⁰ is hydrogen or cyano, R¹¹ is hydrogen,alkyl or alkylcarbonylamino, and R¹² is alkyl.
 10. The transferrecording method according to claim 5 wherein the sublimable dye havingan epoxy group is an indoaniline type dye of the formula: ##STR194##wherein n is 0 or 1, R⁴ is alkyl or alkoxyalkyl, R¹² is alkyl, and Y¹,Y² and X¹ are each hydrogen, methyl, methoxy, halogen, acylamino oralkoxycarbonylamino.
 11. In a transfer recording method which comprisesheating a transfer sheet having a color material layer containing asublimable dye on a base according to the image information received,thereby subliming said sublimable dye and transfer recording it on animage receiving layer of a recording sheet, a transfer recording methodwhich is characterized in that the color material layer of the transfersheet contains a sublimable dye having an acryloyl group or amethacryloyl group and the image receiving layer of the recording sheetcontains an active hydrogen compound.
 12. The transfer recording methodaccording to claim 11 wherein the sublimable dye having an acryloylgroup or a methacryloyl group is a styrylic dye of the formula:##STR195## wherein R¹⁰ is hydrogen or cyano, R¹¹ is hydrogen, alkyl oralkylcarbonylamino, R¹⁸ is alkyl, R¹⁹ is acryloyl or methacryloyl, andX² is --O-- or --NH--.
 13. The transfer recording method according toclaim 11 wherein the sublimable dye having an acryloyl group or amethacryloyl group is an anthraquinone dye of the formula: ##STR196##wherein X⁴ is --O-- or --S--, X⁵ is alkylene, X² is --O-- or --NH--, andR¹⁹ is acryloyl or methacryloyl.
 14. The transfer recording methodaccording to claim 11 wherein the sublimable dye having an acryloylgroup or a methacryloyl group is an indoaniline type dye of the formula:##STR197## wherein n is 0 or 1, R⁴ is alkyl or alkoxyalkyl, R¹⁸ isalkyl, Y¹, Y² and X¹ are each hydrogen, methyl, methoxy, halogen,acylamino or alkoxycarbonylamino, R¹⁹ is acryloyl or methacryloyl, andX² is --O-- or --NH--.
 15. The transfer recording method according toclaim 11 wherein the sublimable dye having an acryloyl group or amethacryloyl group is an azo dye of the formula: ##STR198## wherein A³is optionally substituted phenyl, benzothiazole, imidazole, thiadiazoleor thienyl, A⁴ is optionally substituted phenyl, R¹¹ is hydrogen, alkylor alkylcarbonylamino, R¹⁸ is alkyl, R¹⁹ is acryloyl or methacryloyl,and X² is --O-- or --NH--.
 16. A heat-sensitive transfer recording sheetset which comprises a transfer sheet provided with a color materiallayer containing a sublimable dye, and a recording sheet having an imagereceiving layer capable of undergoing a covalent bond reaction with saidsubliming dye by heating said transfer sheet according to the imageinformation received, a heat-sensitive transfer recording sheet setwhich is characterized in that the color material layer of the transfersheet contains a sublimable dye having a vinylsulfonyl group and theimage receiving layer of the recording sheet contains an active hydrogencompound.
 17. A heat-sensitive transfer recording sheet set whichcomprises a transfer sheet provided with a color material layercontaining a sublimable dye, and a recording sheet having an imagereceiving layer capable of undergoing a covalent bond reaction with saidsubliming dye by heating said transfer sheet according to the imageinformation received, a heat-sensitive transfer recording sheet setwhich is characterized in that the color material layer of the transfersheet contains a sublimable dye having an epoxy group and the imagereceiving layer of the recording sheet contains an active hydrogencompound or an organic acid anhydride.
 18. A heat-sensitive transferrecording sheet set which comprises a transfer sheet provided with acolor material layer containing a sublimable dye, and a recording sheethaving an image receiving layer capable of undergoing a covalent bondreaction with said subliming dye by heating said transfer sheetaccording to the image information received, a heat-sensitive transferrecording sheet set which is characterized in that the color materiallayer of the transfer sheet contains a sublimable dye having an acryloylgroup or a methacryloyl group and the image receiving layer of therecording sheet contains an active hydrogen compound.